source: https://www.securityfocus.com/bid/17483/info
Chipmunk Guestbook is prone to an SQL-injection vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input before using it in an SQL query.
A successful exploit could allow an attacker to compromise the application, access or modify data, or exploit vulnerabilities in the underlying database implementation.
http://www.example.com/user/index.php?SID=[SQL]